1. Field of the Invention
The invention relates to a medical product with a textile component, for example a wound compress, having the features of a multiplicity of openings, with at least two patterns of holes with groups of openings, the diameter of one opening of one hole pattern deviating from the diameter of an opening of another hole pattern in each case by about at least a factor of 5 from one another.
2. Description of the Related Art
In the medical sector, a number of textile products are known which are intended to externally promote wound healing, for example. Known medical products such as wound compresses consist for example of woven fabric, which has the disadvantage that it has a hard surface which adapts poorly to the wound. For this reason, many wound compresses are made up of knitted fabrics which are soft per se. They also have some degree of moisture absorbency. The softness of knitted fabrics arises from the movement of the threads within the interfacing. These abovementioned wound products have the disadvantage that they harden because of exudates emerging from the wound and thus lose their functional ability.
Known compresses have semipermeable membranes of polyurethane which permit the passage and exchange of gases and fluids and have in particular nonadhesive materials on the surface facing the wound in order to prevent them from firmly sticking to the wound. This very type of compress is not able to specifically promote the angiogenesis which is achieved with the surface structure according to the invention. U.S. Pat. No. 5,465,735 describes such a multi-layer wound dressing with a dense nonwoven which is intended in particular to permit less sticking to the wound.
Further possible uses of medical products with a textile component are, for example, the treatment of abdominal wall defects in the groin area or for strengthening soft tissue in other places. A corresponding technique is described in U.S. Pat. No. 5,569,273 which describes a hexagonal net structure of polypropylene monofilament yarns. Large openings are constructed between adjacent vertical mesh rows, into which body tissue can grow into the implant because of the pore structure. However, this product does not promote angiogenesis.
EP 870 820 discloses a nonadhesive wound dressing which, across its active area, has depressions containing a pharmaceutical carrier substance. The depressions are intended only for receiving and delivering an active substance. The nonadhesion of the wound dressing is emphasized.
Finally, EP 931 012 describes a compress which is used for treating wounds in a moist environment and which, by means of an appropriate choice of dressing material, is likewise intended not to adhere to the wound.
Taking this prior art as a basis, it is an object of the invention to make available a medical product which is of the type set out in the introduction and which specifically influences and promotes angiogenesis and the healing process associated with the latter.
It is also an aim of the invention to ensure that such a medical product also remains soft in its textile component even after prolonged contact with the wound.
A further aim of the invention is to ensure that the rigidness of such a medical product can be preset individually at the time of production.
Finally, it is also a further object of the invention to improve angiogenesis and consequently the tissue regeneration in leg ulcers, for example.
According to the invention, this object is achieved by the fact that the surface has a multiplicity of openings, there being at least two patterns of holes with groups of openings, the diameter of one opening of one hole pattern deviating from the diameter of an opening of another hole pattern in each case by about at least a factor of 5 from one another.
The advantage for the patient of using medical products according to the invention lies in the more rapid wound healing, in the reduction of the pain associated with wound treatment, in the shorter time spent in an inpatient department, and in the fact that the cost of treating such wounds is considerably reduced, which is important to the economy. These advantages are achieved by adapting the structural and mechanical properties of the medical product to the properties of the tissue in question.
In the case of leg ulcers, the main focus of wound healing lies in the regeneration of a physiologically functional vascular system. Wound healing is to be seen in the context of scar tissue formation. An intensive scar tissue formation inconveniences the patient because of the poor cosmetic aspect and in particular because of limited mobility. Both of these lead to personal anxiety and in many cases to disability. When the wound has healed, there is unfortunately connective scar tissue left in which the collagen matrix is reconstructed in compact parallel bundles, whereas the meshwork in undamaged skin has mechanically better properties.
Rapid vascularization can lead to uncontrolled formation of the skin capillary system. The capillaries themselves influence the orientation of the collagen fibers.
Mechanical signals in the form of the exertion of a controlled pull on the cells in the wound bed can represent an important activator of the wound response. Mechanical influences on the wound also play a part in collagen genesis because modified stresses during wound closure influence scarring. It is assumed that in order to form a normal collagen architecture a defined physiological mechanical stimulation is required with respect to loading and orientation. In the case of scar tissue, by contrast, the anisotropy of the collagen network and the dimensions of the collagen fibers are increased.
In contrast to the feature of nonadhesion to the wound bed, on which feature emphasis is placed in the prior art, growth of tissue into the medical article is here desired and advantageous.
The invention makes available a wound treatment system developed on a textile basis which controls tissue formation and positively influences angiogenesis by acting as a framework. The support for the layer according to the invention is dependent on the application. The use of the medical products according to the invention is possible in many areas. One area of use concerns the treatment of large wounds, burns or in surgical applications, for example for hernia meshes. These procedures require treatment systems which make it possible to minimize scar formation. At the same time, it is also possible for the medical products to include mannose-6-phosphate or other collagen-regulating means, or factors which promote tissue regeneration, for example growth factors of the TGF-b family.
The medical product can be used in many applications where the embroidery-specific properties such as the controlled mechanical properties of an embroidery, the local variation in the mechanical design and the specific porosity can be of great advantage. In addition to the stated compresses and hernia meshes, these include abdominal wall replacements, artificial blood vessels and artificial ligaments. In the case of the latter, the embroidery technique can be used to pass from a first specific structure, where the ligament is to grow on and where load transmission takes place, to a second and different structure in the ligament area. A further application is the formation of augmentation embroideries for reconstruction of the jaw bone in the dental sector.
Depending on the desired mechanical and structural properties of the textile, different yarn types are used. These can include fibrous, multifilament or monofilament yarns, which can also be untreated, antimicrobially pretreated, gel-coated and can be present in different titers.
By using embroidery technology, the knot size and the nature of the linking can likewise be preset.
The invention is described in more detail below on the basis of illustrative embodiments.